The multiple signal classification is also MUSIC algorithm with higher resolving power, estimation precision and stability, which is also a hot research field all the time to DOA estimation on radar signal processing. In this paper, we analysed and studied the inaccuracy factors of DOA estimation on MUSIC algorithm and discussed the estimation performances and features of MUSIC algorithm. The theory analysis and simulation results demonstrate that, to the non-correlation signal, MUSIC algorithm is also an effective method for the measure of target direction angle.